Migraines

A significant number of people with fibromyalgia also experience migraines and/or tension headaches, says Robert Duarte, MD, director of the Pain Institute at the North Shore–Long Island Jewish Health System, in Manhasset, N.Y.

"An underlying disturbance in the brain chemicals serotonin and norepinephrine plays a role in causing headaches and fibromyalgia," he says.

Antidepressants that target these brain chemicals may relieve migraine pain, he adds. Tension headache may also respond to biofeedback.

Autoimmune diseases

Up to one-quarter of people with inflammatory autoimmune diseasesincluding rheumatoid arthritis (RA), lupus, Sjögren's syndrome, and ankylosing spondylitisalso experience fibromyalgia symptoms. The precise nature of this connection is not yet understood.

Fibromyalgia is not an inflammatory disease, but some research suggests that RA and other inflammatory diseases may somehow increase the risk for fibromyalgia.

Restless legs

Sleeplessness and other sleep problems are common for fibromyalgia patients, says Lesley Arnold MD, a psychiatrist at the University of Cincinnati College of Medicine. Restless legs, or the overwhelming urge to move your legs when resting, may be up to 11 times more common in people with fibromyalgia than those without it.

Exactly how the two are linked is not fully understood, but many fibromyalgia treatments also improve restless legs, not to mention overall sleep quality.

Pelvic pain

People with fibromyalgia are more likely to report pelvic pain, bladder irritability, and menstrual cramps, and some of the medicines that relieve fibromyalgia symptoms can also ease these other pains.

More research is needed to understand how these pain conditions are related to fibromyalgia.

Depression and anxiety

More than half of people with fibromyalgia also experience mental or emotional problems, such as depression and anxiety, at some point in their lives. "It is less of a causal or chicken-and-egg relationship," Dr. Arnold says. "(But) they may share common, underlying causes."

A deficit of the brain chemicals serotonin and norepinephrine is involved in both mood and pain disorders, she says. Many medications used to treat fibromyalgia are also antidepressants.

Obesity

"Obesity and fibromyalgia share a complicated relationship, and it's one that we can't ignore," says Dr. Arnold.

Many people with fibromyalgia lead sedentary lives due to their chronic pain, and a lack of regular physical activity increases their risk of becoming overweight or obese.

"Being overweight places more mechanical stress on your joints, which can cause more pain and aggravate the fibromyalgia," Dr. Arnold says. Plus, fat stores are pro-inflammatory, which can also exacerbate pain.